Chimney liners

ABSTRACT

A tubular chimney liner is supported within the outer tubular shell of a chimney structure by tensioning means connected between the liner and the shell for applying an upward force to the liner in excess of its weight, and tethering means connected to the liner adjacent to its bottom end for maintaining the bottom end of the liner in a substantially constant position. The liner is thus supported under longitudinal tension, and changes in length due to thermal changes are taken up at its upper end.

United States Patent 91 Wood [ 1 Dec. 25, 1973 1 1 CHIMNEY LINERS [76] Inventor: Geoffrey Brian Wood, R. R. No. 1,

18th Ave., Richmond Hill, Ontario, Canada [22] Filed: July 11, 1972 [21] Appl. No.: 270,863

3,531,845 10/1970 Senftleben 110/184 X FOREIGN PATENTS OR APPLICATIONS 589,090 6/1947 Great Britain 1 10/184 Primary Examiner-William F. ODea Assistant Examiner-Peter D. Ferguson AttorneyJ. A. Legris [57] ABSTRACT A tubular chimney liner is supported within the outer tubular shell of a chimney structure by tensioning means connected between the liner and the shell for applying an upward force to the liner in excess of its weight, and tethering means connected to the liner adjacent to its bottom end for maintaining the bottom end of the liner in a substantially constant position. The liner is thus supported underlongitudinal tension, and changes in length due to thermal changes are taken up at its upper end.

10 Claims, 3 Drawing Figures [56] Reierences Cited UNITED STATES PATENTS 2,009,378 7/1935 Bates 1. 110/184 X 3,233,567 2/1966 Goldfield.... 3,489,072 1/1970 Secor 98/58 I ll; 1 l1 12 PATENTED DEC 2 5 I975 SHEEI 1 0F 2 CHIMNEY LINERS This invention relates to chimneys of the type having a vertical tubular shell with a tubular liner supported vertically within the shell. The tubular shell of such a chimney may be of concrete, metal or masonry, while the liner may be of steel or, in more recent installations, of glass reinforced polyester resin.

In one known method of supporting a tubular liner within the outer shell of a chimney, the bottom end of the liner is mounted on a fixed base so that the liner is in compression under its own weight. This creates serious problems in the case of tall chimneys, due to buckling of the liner under the ardous conditions of chimney operation, and liners under compression frequently fail with serious consequences.

In another known method, the liner is suspended from its upper end so that it remains in tension. This method also has its disadvantages, however, for in order to accommodate thermal expansion and contraction of the liner it is necessary to provide expansion joints which will obviate relative movements between the chimney flue or breach duct and the breach in the liner to which it is connected. Expansion joints which have been used for this purpose are highly susceptible to failure owing to their inability to withstand the thermal stresses to which they are subjected, and, more particularly, owing to their vulnerability to the effects of fly ash.

It is an object of the present invention to provide a means for supporting chimney liners which does not suffer from the disadvantages or limitations referred to above.

According to the present invention a tubular chimney liner is supported within the outer tubular shell of a chimney structure by tensioning means connected between the liner and the shell for applying an upward force to the liner in excess of its weight, and tethering means connected to the liner adjacent to its bottom end for maintaining the bottom end of the liner in a substantially constant position. The liner is thus supported under longitudinal tension, and changes in length due to thermal changes are taken up at its upper end.

The tension means may comprise a plurality of pulleys, each of which is weighted by a dead weight.

In order that the invention may be readily understood, one embodiment thereof will now be described by way of example with reference to the accompanying drawings. In the drawings:

FIG. 1 is a broken away sectional elevation taken through the vertical axis of a chimney structure according to the invention;

FIG. 2 is a section on line 22 in FIG. 1, and

FIG. 3 shows a detail of construction.

The chimney illustrated in the drawings comprises a vertical tubular outer shell 10, which tapers upwardly. The shell is of concrete, and has an opening 11 near its lower end to accommodate a breach duct 12. At the base of the chimney is a conventional fixed grillage 13. A tubular liner 14 is supported vertically within the shell, the bottom 14' of the liner resting on the grillage 13 as shown. The liner 14, which may be of metal or of glass reinforced polyester resin, is made up of a number of tubular sections joined in end to end relation. The sections are typically 30 feet long. Towards the bottom end of the liner is a flared section 15, to which the breach duct 12 is connected.

The liner 14 is provided with an upper attachment means 16 spaced from its top end 14", the upper attachment means comprising a plurality of plates 17 projecting radially outwardly from a ring 18 secured to the liner. The liner is also provided with a lower attach ment means 19 consisting of a plurality of radially outwardly projecting plates secured to the liner adjacent to its bottom end. The liner is supported within the shell 10 by means of pulley 20 arranged around the liner 14 in the annular space between the liner and the shell. Each pulley has a velocity ratio, in the present example, of 7:1, and is connected between a respective one of the plates 17 of the attachmentmeans l6 and a support grillage 21 projecting inwardly from the shell 10. Each pulley is weighted by a dead weight 22, so that the pulleys together apply an upward force to the liner 14 a little in excess of the weight of the liner. Typically, the upward force would be about 5 percent in excess of the weight of the liner. In order to prevent the liner 14 from rising within the shell, the bottom end of the liner is tethered by means of tethering cables 23 connected between the lower attachment means 19 and the base grillage 13. The bottom end of the liner is thus held in a substantially constant position, and the liner is supported under longitudinal tension between the upper and lower attachment means.

The upper end 14" of the liner projects from the upper end of the shell 10 and is surmounted by a cowl 24.

In the illustrated construction, the lineris maintained in tension rather than compression, for the greater part of its length. In consequence the risk of failure through buckling under compression is practically eliminated. Furthermore, since the liner does not have to withstand longitudinal compressive loads, the liner thickness can be greatly reduced with "considerably saving of material. For example, in the case of a chimney liner of glass reinforced polyester, the liner being 800 feet long and 36 feet wide, the liner wall need be only one half inch thick, that is to say, about five times less than would usually be considered necessary for a liner in compression.

Since the bottom end of the liner is fixed, the need for expansion joints to accommodate relative movements between the liner and the breach duct, due to temperature variations, is eliminated. In this case the liner is permitted to expand and contract, such movements being accommodated by the pulleys 20 which continue to apply a tensioning force to the liner despite such movements; the upper end 14" of the liner, where it projects from the shell, will of course vary in height as the liner undergoes changes in length, but such variations in height are permissible since there is no constraining structure between the upper end of the liner and the fixed shell.

Although the drawings show a single set of pulleys 20 for supporting the liner 14, it is to be understood the practical embodiment of the invention would normally include a number of longitudinally spaced sets of pulleys, each set of pulleys being connected between its own support grillage, corresponding to the grillage 21, and an attachment means on the liner. In erecting the liner the uppermost section of the liner is first hoisted by means of the pulleys 20; the next section is then hoisted by the second set of pulleys into a position in which it can be joined to the first section. Successive sections are hoisted into position and joined in the same way. A detail of the assembled structure, showing two liner sections supported within the shell, is illustrated in FIG. 3. In this figure the liner sections are denoted by the numerals, 14a, 141;; the pulleys are denoted by the numerals 2011, b, and the respective attachment means by 16a, 161;.

What I claim as my invention is:

' 1. in a chimney having a vertical tubular shell, a tubular liner supported vertically within the shell, tensioning means connected between the liner and the shell for applying an upward force to the liner in excess of its weight, and tethering means connected to the liner adjacent to its bottom end for maintaining said bottom end of the liner in a substantially constant position.

2. In a chimney having a vertical tubular shell, a tubular liner supported vertically within the shell, the liner having upper and lower, outwardly projecting, longitudinally spaced attachment means, said lower attachment means being adjacent to the bottom end of the liner, tensioning means connected between the upper attachment means and the shell for applying an upward force to the liner in excess of its weight, and tethering means connected to said lower attachment means for maintaining the bottom end of the liner in a substantially constant position, whereby the liner is supported under longitudinal tension between said upper and lower attachment means.

3. The combination claimed in claim 2, wherein the upper end of the liner projects above the upper end of the shell.

4. In a chimney having a vertical tubular shell, a grillage structure located at the base of the shell, support means projecting inwardly from the shell at an intermediate position between its ends, a tubular liner extending vertically within the shell, the liner having upper and lower, inwardly projecting, longitudinally spaced attachment means, the lower attachment means being adjacent to the bottom end of the liner and the upper attachment means being spaced from the top end of the liner at a position lower than said support means, tensioning means connected between said upper attachment means and said support means for applying an upward force to the liner in excess of its weight, and tethering means connected between said lower attachment means and said grillage structure for maintaining the bottom end of the liner in a substantially constant position.

5. The combination claimed in claim 4, wherein the top end of the liner projects from the upper end of the shell.

6. The combination claimed in claim 5, wherein each of said upper and lower attachment means comprises a ring of radial projections, said tensioning means and said tethering means being respectively connected to said rings of projections.

7. The combination claimed in claim 6, wherein the tensioning means comprises a plurality of pulleys connected between said support means and the upper attachment means, each pulley being tensioned by a dead weight to apply said upward force.

8. The combination claimed in claim 7, wherein the support means comprises an annular grillage.

9. in a chimney comprising a vertical tubular shell having a base grillage, anchorage means projecting inwardly from the shell at a position spaced from its upper end, a tubular liner extending vertically within the shell, the tubular liner having a bottom end which is tethered to the base grillage by tethering cables and a top end which projects from the upper end of the shell, the tubular liner further providing outwardly projecting attachment means at a position spaced downwardly from said anchorage means, the liner being supported by a plurality of pulleys connected between said attachment means and said anchorage means, the pulleys being weighted by dead weights to apply an upward force to the liner in excess of its weight.

10. The combination claimed in claim 9, wherein the tubular liner comprises a plurality of tubular sections connected together in end to end relation. 

1. In a chimney having a vertical tubular shell, a tubular liner supported vertically within the shell, tensioning means connected between the liner and the shell for applying an upward force to the liner in excess of its weight, and tethering means connected to the liner adjacent to its bottom end for maintaining said bottom end of the liner in a substantially constant position.
 2. In a chimney having a vertical tubular shell, a tubular liner supported vertically within the shell, the liner having upper and lower, outwardly projecting, longitudinally spaced attachment means, said lower attachment means being adjacent to the bottom end of the liner, tensioning means connected between the upper attachment means and the shell for applying an upward force to the liner in excess of its weight, and tethering means connected to said lower attachment means for maintaining the bottom end of the liner in a substantially constant position, whereby the liner is supported under longitudinal tension between said upper and lower attachment means.
 3. The combination claimed in claim 2, wherein the upper end of the liner projects above the upper end of the shell.
 4. In a chimney having a vertical tubular shell, a grillage structure located at the base of the shell, support means projecting inwardly from the shell at an intermediate position between its ends, a tubular liner extending vertically within the shell, the liner having upper and lower, inwardly projecting, longitudinally spaced attachment means, the lower attachment means being adjacent to the bottom end of the liner and the upper attachment means being spaced from the top end of the liner at a position lower than said support means, tensioning means connected between said upper attachment means and said support means for applying an upward force to the liner in excess of its weight, and tethering means connected between said lower attachment means and said grillage structure for maintaining the bottom end of the liner in a substantially constant position.
 5. The combination claimed in claim 4, wherein the top end of the liner projects from the upper end of the shell.
 6. The combination claimed in claim 5, wherein each of said upper and lower attachment means comprises a ring of radial projections, said tensioning means and said tethering means being respectively connected to said rings of projections.
 7. The combination claimed in claim 6, wherein the tensioning means comprises a plurality of pulleys connected between said support means and the upper attachment means, each pulley being tensioned by a dead weight to apply said upward force.
 8. The combination claimed in claim 7, wherein the support means comprises an annular grillage.
 9. In a chimney comprising a vertical tubular shell having a base grillage, anchorage means projecting inwardly from the shell at a position spaced from its upper end, a tubular liner extending vertically within the shell, the tubular liner having a bottom end which is tethered to the base grillage by tethering cables and a top end which projects from the upper end of the shell, the tubular liner further providing outwardly projecting attachment means at a position spaced downwardly from said anchorage means, the liner being supported by a plurality of pulleys connected between said attachment means and said anchorage means, the pulleys being weighted by dead weights to apply an upward force to the liner in excess of its weight.
 10. The combination claimed in claim 9, wherein the tubular liner comprises a plurality of tubular sections connected together in end to end relation. 